The broad, long-term objective of this proposal is to test the overall hypothesis that Neutrophil Extracellular Traps (NETs) contain posttranslationally modified self-antigens, and that the resultant, normally cryptic epitopes can break tolerance to self and induce an immune response in SLE. This proposal will use antigen microarrays, a technology developed at Stanford, to study serum derived from murine models and human SLE patients, including those seen in Stanford's rheumatology clinic. The aims include: (i.) to profile broad covalent modification patterns in Neutrophil Extracellular Traps (NETs), as a potential source of self- antigens;(ii.) to test the hypothesis that exposure to NETs can induce SLE in a murine model;(iii.) to profile autoantibodies from mice treated with NETs, using antigen microarrays;and (iv.) to profile autoantibodies from a large cohort of highly characterized human SLE patients. Understanding the temporal relationship between cell activation, autoantibody formation, and end-organ damage is critical to solving SLE,with immediate implications for human immune monitoring and development of targeted therapeutics. PUBLIC HEALTH RELEVANCE: The proposed research plans to harness the power of newly-developed high-throughput technologies to discover and validate biomarkers in systemic lupus erythematosus (SLE), an autoimmune disease where the immune system produces antibodies that attacks the body's own tissues and organs. SLE has long been very difficult to diagnose properly - it is often called the "great imitator", due to many of its symptoms resembling those of other, more common diseases, with new treatment strategies only recently developed for improving the quality of life for the patient. The proposed research, if successful, would immediately benefit SLE patients by providing them with more accurate and informative diagnoses that may suggest more effective courses of treatment, and would have a major impact on many areas of human medicine including transplantation and the study of numerous other autoimmune diseases.